Bacon, Potato, Carrot, Onion Casserole

This can be made the night before, refrigerated and cooked the next day.Quick, easy and delicious. Serve with hot biscuits.
You can use precooked bacon pieces or turkey bacon or small pieces of ham!
NOTE: i HAVE CHANGED THE AMOUNT OF MAYO (IT WAS A MISTAKE WHEN I FIRST PUBLISHED)

This LOOKED like a no-fail recipe, and even eating it, we kept saying "This wants to be good. It really does" but it missed the mark. We're thinking if we add 6 eggs, delete 1 cup of mayo and sprinkle with cheese it will be amazing. The inch-deep pool of grease that baked down into the bottom of the pan was gross to look at, but to be expected based on mayo/butter content level.

Note: Delete 1/2 tsp salt if using bonapetite seasoning, that has salt, pepper and garlic. If you don't have that seasoning, use 1 clove crushed garlic or 1 tsp minced fresh garlic in a jar, the salt and white pepper.

Caution: Use mustard only if you love the flavor of mustard because it will really flavor when combined with the mayonnaise.